First start plug-in architecture

src/plugin/plugin.cpp

@@ -19,14 +19,17 @@
 
 #include "plugin.h"
 
+#include <boost/algorithm/string/predicate.hpp>
 #include <boost/dll/shared_library.hpp>
 
+#include <algorithm>
+#include <filesystem>
 #include <sstream>
 #include <stdexcept>
 
 namespace {
-	using plugin_abi_fn = ifcopenshell::plugin::abi_info(*)();
-	using plugin_metadata_fn = ifcopenshell::plugin::metadata(*)();
+	using plugin_abi_fn = ifcopenshell::plugin::abi_info();
+	using plugin_metadata_fn = ifcopenshell::plugin::metadata();
 
 	std::string compiler_id() {
 #if defined(_MSC_VER)
@@ -101,6 +104,13 @@ bool ifcopenshell::plugin::module::is_loaded() const {
 	return data_->library_ && data_->library_->is_loaded();
 }
 
+boost::dll::shared_library& ifcopenshell::plugin::module::library() const {
+	if (!data_->library_) {
+		throw std::runtime_error("Plugin module is not dynamic");
+	}
+	return *data_->library_;
+}
+
 ifcopenshell::plugin::manager::manager() = default;
 
 void ifcopenshell::plugin::manager::add_search_path(const std::filesystem::path& path) {
@@ -111,6 +121,39 @@ const std::vector<std::filesystem::path>& ifcopenshell::plugin::manager::search_
 	return search_paths_;
 }
 
+std::vector<std::filesystem::path> ifcopenshell::plugin::manager::discover(const std::string& basename_prefix) const {
+	std::vector<std::filesystem::path> result;
+	const auto suffix = boost::dll::shared_library::suffix().string();
+	const auto prefixed_basename = "lib" + basename_prefix;
+
+	for (const auto& search_path : search_paths_) {
+		if (!std::filesystem::exists(search_path) || !std::filesystem::is_directory(search_path)) {
+			continue;
+		}
+
+		for (const auto& entry : std::filesystem::directory_iterator(search_path)) {
+			if (!entry.is_regular_file()) {
+				continue;
+			}
+
+			const auto filename = entry.path().filename().string();
+			if (!boost::algorithm::iends_with(filename, suffix)) {
+				continue;
+			}
+			if (!boost::algorithm::istarts_with(filename, basename_prefix) &&
+				!boost::algorithm::istarts_with(filename, prefixed_basename)) {
+				continue;
+			}
+
+			result.push_back(entry.path());
+		}
+	}
+
+	std::sort(result.begin(), result.end());
+	result.erase(std::unique(result.begin(), result.end()), result.end());
+	return result;
+}
+
 ifcopenshell::plugin::module ifcopenshell::plugin::manager::load(const std::filesystem::path& path) const {
 	auto library = std::make_shared<boost::dll::shared_library>(path, boost::dll::load_mode::default_mode);
 	auto abi = library->get_alias<plugin_abi_fn>("ifcopenshell_plugin_abi_v1")();

src/plugin/plugin.h

@@ -22,6 +22,8 @@
 
 #include "plugin_api.h"
 
+#include <boost/dll/shared_library.hpp>
+
 #include <cstdint>
 #include <filesystem>
 #include <memory>
@@ -68,11 +70,17 @@ public:
 	bool is_dynamic() const;
 	bool is_loaded() const;
 
+	template <typename T>
+	decltype(auto) get_alias(const char* name) const {
+		return library().get_alias<T>(name);
+	}
+
 private:
 	struct data;
 	std::shared_ptr<data> data_;
 
 	explicit module(std::shared_ptr<data> data);
+	boost::dll::shared_library& library() const;
 
 	friend class manager;
 };
@@ -84,6 +92,7 @@ public:
 	void add_search_path(const std::filesystem::path& path);
 	const std::vector<std::filesystem::path>& search_paths() const;
 
+	std::vector<std::filesystem::path> discover(const std::string& basename_prefix) const;
 	module load(const std::filesystem::path& path) const;
 
 private:

src/plugin/plugin_api.h

@@ -20,7 +20,6 @@
 #ifndef PLUGIN_API_H
 #define PLUGIN_API_H
 
-#ifdef IFC_SHARED_BUILD
 #ifdef _WIN32
 #ifdef PLUGIN_EXPORTS
 #define PLUGIN_API __declspec(dllexport)
@@ -30,8 +29,5 @@
 #else
 #define PLUGIN_API __attribute__((visibility("default")))
 #endif
-#else
-#define PLUGIN_API
-#endif
 
 #endif